It is known to employ an elongated cylinder or tube containing a plurality of perforated plates to disperse a solid, semi-solid, or viscous material into a fluid. Thus, for example, in U.S. Pat. No. 2,125,245, there is disclosed a vertically positioned tube, provided with a number of transverse, perforated plates, for dispersing materials such as asphalt, paraffin, and thermoplastic hydrocarbons into a fluid such as water. Baffles, having a restricted passage or opening along the margin thereof, are located between each of the perforated plates. The asphalt, or other material, is heat liquified before it is introduced into the cylinder or tube. Exemplary of another device for mixing or blending materials is that shown in U.S. Pat. No. 3,045,984. The device of that patent comprises an elongated cylinder having a series of baffles secured to opposite sides of the inner wall of the cylinder. Each of the baffles is provided with an opening therethrough to aid in mixing or blending the materials in the cylinder as they pass from the inlet to the outlet end thereof. Other patents showing apparatus for intermixing materials and fluids include U.S. Pat. Nos. 2,312,639; 2,391,110; 3,885,368; 4,068,830; and 4,136,976. None of the aforementioned patents, however, are concerned with the problems involved in diluting certain polymer solutions, especially polymer solutions of the type used in the secondary and tertiary recovery of oil.